Device for transporting and/or storing

ABSTRACT

The present invention relates to a device for transporting and storing of a powder or liquid medium, comprising (a) a structurally stable outer container having an electrically conducting inner surface, a top side that is open and capable of receiving an inner container, and a bottom section comprising a plurality of recesses wherein each recess can receive a pronged platform of a cargo moving device; and (b) an inner container capable of holding said medium having a top section, an opening in said top section for filing and discharging said medium, and one or more walls. These walls are made of a plastic material, are adjacent to said inner surface of said outer container, and have an outer surface. The outer surface has at least one electrically conductive layer that is in electrical contact with the outer container&#39;s inner surface. Moreover, invention could optionally include a plastic pallet having an electrically conductive layer that is in contact with the outer container.

CROSS REFERENCES TO RELATED APPLICATIONS

[0001] This application is the U.S. national phase entry which claimspriority benefit under 35 U.S.C. § 371 of PCT International ApplicationSerial No. PCT/EP02/05194 filed May 10, 2002, which, in turn, claimspriority of German Application DE 201 07 962.3 filed on May 11, 2001.

FIELD OF INVENTION

[0002] This invention relates to a device for transporting and storing apowder or liquid medium, the device comprising (a) an outer containerwhich is predominantly stable with respect to its shape, open on the topside, and is formed pallet-like in its bottom, and (b) an innercontainer for accommodating the medium, which comprises a top sectionhaving an opening for filling and discharging the medium, said innercontainer being adjacent to the outer container's inner surface andbeing, if necessary, secured by a covering element that may be attachedto the outer container, wherein the inner container has at least onewall made of plastic materials.

BACKGROUND

[0003] A variety of conventional devices for transporting and storingpowder and liquid medium, including those comprising an outer containerand inner container having a volume of several hundred liters, are usedmore and more often in various application. In many of such conventionaldevices, the inner container comprises plastic materials, wherein thewall can comprise one or several layers. In addition, the innercontainer has an opening for filling and discharging through itsso-called top section and is secured in many cases by means of acovering element in the outer container. The inner container is oftenrealized with a relatively thin wall and is enclosed within an outercontainer for the purpose of its stabilization. The outer container maycomprise metal or plastic materials. In most cases, the outer containeris arranged on a pallet that comprises wood, metal or plastic materials.

[0004] Applicants have recognized that a metallic outer container isundesired in many fields, in particular in the fields of chemicalindustry and food processing. For example, in fields in which acidsand/or corrosive materials are used, the danger of corroding exists ifthe outer container is made of steel. Such danger of corroding may beavoided if the outer container is made of stainless steel. However, sucha container comprising stainless steel is expensive and lavish withrespect to its making.

[0005] To eliminate the aforementioned disadvantages, the outercontainer of certain conventional devices have been produced fromplastic materials, wherein the wall of said container can be made of oneor of several layers as well. Such an outer container made of plasticmaterials tends to be inexpensive in its production and not subject tocorrosion.

[0006] However, Applicants have further recognized that there are fieldsin industry in which conventional storage devices that have an innercontainer and/or outer container being made of plastic materials cannotbe used for reasons of security with respect to explosions. By usingplastic materials, the danger exists that electrostatic charging mayoccur due to poor electrical conductance. This may also lead toelectrostatic surface charge effects.

SUMMARY OF THE INVENTION

[0007] Therefore, the object of the present invention is to design adevice for transporting and storing a powder or a liquid medium, whereinat least the inner container of said device comprises plastic materials,characterized in that electrostatic surface charge effects are lesslikely to occur than in conventional devices.

[0008] According to the invention, this object is met by using a deviceas described herein, wherein the parts of the device that compriseplastic materials have at least one electrically conducting layer ontheir outer surfaces and wherein said electrically conducting layers aremutually electrically conductive connected.

[0009] Furthermore, the invention relates to a device for transportingand storing a powder or liquid medium, comprising (a) a structurallystable outer container having an electrically conducting inner surface,a top side that is open and capable of receiving an inner container, anda bottom section comprising a plurality of recesses wherein each recesscan receive a pronged platform of a cargo moving device; and (b) aninner container capable of holding said medium, the inner containerhaving a top section, an opening in said top section for filing anddischarging said medium, and one or more walls. At least one wall of thecontainer is made of a plastic material, is adjacent to the innersurface of the outer container, and has an outer surface. The outersurface of the inner container has at least one electrically conductivelayer that is in electrical contact with the outer container's innersurface. Moreover, invention could optionally include a plastic pallethaving an electrically conductive layer that is in contact with theouter container.

[0010] By using this design, it is possible to conduct electricalcharges away from the container so that electrostatic surface chargeeffects cannot occur. If the electrically conductive layer comprises aplastic material mixed with an electrically conducting filling material,this layer may be kept extremely thin. This leads to the advantage thatrelatively little of the considerably expensive electrically conductingplastic material is needed. Also, the electrically conducting layer doesnot need to display good structural properties.

[0011] According to certain preferred embodiments of the presentinvention, the device is characterized in that the electricallyconductive layer comprises an electrically conductive filling materialmixed with plastic materials.

[0012] Furthermore, in certain preferred embodiments, the device ischaracterized in that the electrically conductive layer has anelectrical resistance of equal to or less than 107 Ohms.

[0013] Furthermore, in certain preferred embodiments, the device ischaracterized in that the non-conductive inner layer of the innercontainer has a wall thickness of no more than three mm.

[0014] Furthermore, in certain preferred embodiments, the device ischaracterized in that the inner layer of the inner container comprises aplastic material of high purity that releases less than 100 parts pertrillion of each metallic impurity into the medium contained within theinner container.

[0015] Furthermore, in certain preferred embodiments, the device has atube for filling and discharging medium within the inner containercharacterized in that the tube for filling and discharging comprises aplastic material that is mixed with an electrically conductive fillingmaterial.

[0016] The present invention is further explained by making reference tothe following figures.

BRIEF DESCRIPTION OF THE DRAWINGS

[0017]FIG. 1A depiction of the device according to the invention inperspective.

[0018]FIG. 2A different embodiment of the device according to theinvention.

[0019]FIG. 3A cross-sectional view of the lower area of the edge of adevice according to the invention.

DETAILED DESCRIPTION OF THE INVENTION AND PREFERRED EMBODIMENTS

[0020] A device for the transport and the storage of a powder or liquidmedium is shown in FIGS. 1 and 2, respectively. This device comprises anouter container 4 that is rectangular-box-shaped and is made of aplastic material in the case of the example shown. However, this outercontainer 4 may also be made of metal, e.g. of sheet metal. The bottomof the outer container 4 is either formed as a pallet or rests on apallet 5. The outer container 4 is designed to be open on the top. Thewall of this outer container 4 is made of a plastic material and may bedesigned to have one or several layers. The outer container 4accommodates a relatively thin-walled inner container 1 that comprises aplastic material of high purity that is suited to accommodate themedium. The purity of the plastic material of the inner layer issufficiently high so that said plastic material releases less than 100ppt of metallic impurities, possibly contained within the plasticmaterial, into the medium. The inner container 1 not only rests on thebottom of the outer container 4, but also on the inner side of thejacket body 6 of the outer container 4. The inner container 1 has anopening for filling located on its upper bottom that is formed by meansof a spout 2 in combination with the outer thread, wherein said openingis closed by means of a cover. This opening for filling may also be usedas an opening for discharging, whereby it is necessary to place adischarge tube onto the spout 2, wherein said discharge tube may also beused as a filling tube and is immersed into the medium that is containedinside the inner container. This tube for filling and discharging isadvantageously made of an electrically conductive plastic material thatis mixed with an electrically conductive filling material. In the caseof the examples shown, the inner container 1, however, contains in itslower area an opening for discharge 3 that is equipped with a closingdevice, wherein said opening for discharge is located in a gap of theouter container 4.

[0021] In the drawings with respect to the examples of FIGS. 1 and 2,the upper rim 7 of the outer container 4 protrudes over the upper bottomof the inner container 1 by a given margin. A covering element 8 with arim for attaching 14 is plugged onto this rim 7. Said covering elementis advantageously made of plastic materials. According to FIG. 1 of thedrawing, said covering element 8 only covers a part of the top of theinner container 1, wherein in the case of FIG. 2 the covering element 8completely covers the top of the inner container 1 and therefore alsothe outer container 4. In the examples shown in FIGS. 1 and 2, theattaching rim 14 of the covering element 8 can be attached to the rim 7of the outer container 4 by screwing. Furthermore, the covering element8 has an indentation 9 that surrounds the spout 2 of the inner container1 by means of an opening 10, wherein said indentation lies on top of asealing device 11 on the upper bottom of the inner container 1.Furthermore, an overflow-groove 12 is shaped into the covering element 8allowing, for example, that a liquid medium being spilled during theprocess of filling can be guided to the outside and discharged via theopenings 13.

[0022] As demonstrated in FIG. 3, the inner container 1 on the one handrests on the bottom 15 of the outer container 4 and lies flush with theinner area of the jacket body 6. However, the depiction of FIG. 3 alsoshows that the wall 16 of the inner container 1 that is made of aplastic material and that may display a thickness of up to threemillimeters is equipped at its outer surface with a layer 17 made of anelectrically conductive plastic material. This layer 17 that is made ofplastic material is realized as an extremely thin layer since the layerdoes not have to perform any structural function. Conductivity isachieved by means of adding an electrically conductive filling materialto the plastic material. The electric resistivity of layer 17 is equalto or less than 107 Ohms.

[0023]FIG. 3 of the drawing also shows the set-up of the wall 18 of theouter container 4. Said wall comprises a supporting layer 19 that ismade of a plastic material and that may be realized in one or in severallayers. In addition, this wall 18 also has an outer layer 20 that ismade of an electrically conducting plastic material, similarly to thecase of the inner container 1. Said layer also displays an extremelysmall thickness. This layer 20 also has no structural functions toperform. In the case of the example chosen, the outer container 4 restson the pallet 5, wherein said pallet is connected to the outer container4 by means of a clip. In the example chosen, this pallet 5 alsocomprises a plastic material, wherein the outer surface is equipped witha layer 21 made of an electrically conductive plastic material. Thecovering element 8 may also be made according to a similar design, i.e.contain an electrically conductive layer. This ensures that noelectrostatic charging may occur, possibly leading to electrostaticsurface charges.

1. Device for transporting and/or storing of a powdery or liquid medium,comprising an outer container, which is predominantly stable withrespect to its shape, open on the topside and is fomred pallet-like inits bottom, for an inner container accommodating the medium, displayingan upper bottom with an opening for filling and/or discharging locatedtherein, said inner container being adjacent to the outer container'sinner surface and being, if necessary, secured by a covering elementthat may be attached to the outer container, wherein at least the innercontainer has a wall made of a plastic material, characterized in thatthe parts of the device made of plastic (1, 4, 5) have at least oneelectrically conductive layer (17, 20, 21) on their outer surfaces andare mutually electrically connected.
 2. Device according to claim 1characterized in that the electrically conductive layer (17, 20, 21)comprises an electrically conductive filling material mixed with plasticmaterials.
 3. Device according to claim 1 or 2, characterized in thatthe electrically conductive layer (17, 20, 21) has an electricalresistance of equal to or less than 10⁷ Ohms.
 4. Device according to atleast one of the claims 1 to 3, characterized in that the non-conductiveinner layer of the inner container (1) has a wall strength of no morethan three mm.
 5. Device according to at least one of the claims 1 to 4,characterized in that the inner layer of the inner container (1)comprises a plastic material of high purity that releases less than 100ppt of each metallic impurity, respectively, into the filling material.6. Device according to at least one of the claims 1 to 4, having a tubefor filling and discharging, which immerses into said medium,characterizied in that the tube for filling and discharging comprises aplastic material that is mixed with an electrically conductive fillingmaterial.